1. Field of the Invention
The invention relates to a method for improving the utilization of the production potential of transgenic plants.
2. Description of Related Art
In recent years, there has been a marked increase in the proportion of transgenic plants in agriculture, even if regional differences are still noticeable to date. Thus, for example, the proportion of transgenic maize in the USA has doubled from 26% to 52% since 2001, while transgenic maize has hardly been of any practical importance in Germany. However, in other European countries, for example in Spain, the proportion of transgenic maize is already about 12%.
Transgenic plants are employed mainly to utilize the production potential of respective plant varieties in the most favourable manner, at the lowest possible input of production means. The aim of the genetic modification of the plants is in particular the generation of resistance in the plants to certain pests or harmful organisms or else herbicides and also to abiotic stress (for example drought, heat or elevated salt levels). It is also possible to modify a plant genetically to increase certain quality or product features, such as, for example, the content of selected vitamins or oils, or to improve certain fibre properties.
Herbicide resistance or tolerance can be achieved, for example, by incorporating genes into the useful plant for expressing enzymes to detoxify certain herbicides, so that a relatively unimpeded growth of these plants is possible even in the presence of these herbicides for controlling broad-leaved weeds and weed grasses. Examples which may be mentioned are cotton varieties or maize varieties which tolerate the herbicidally active compound glyphosate (Roundup®), (Roundup Ready®, Monsanto) or the herbicides glufosinate or oxynil.
More recently, there has also been the development of useful plants comprising two or more genetic modifications (“stacked transgenic plants” or multiply transgenic crops). Thus, for example, Monsanto has developed multiply transgenic maize varieties which are resistant to the European corn borer (Ostrinia nubilalis) and the Western corn rootworm (Diabrotica virgifera). Also known are maize and cotton crops which are both resistant to the Western corn rootworm and the cotton bollworm and tolerant to the herbicide Roundup®.